A 12 volt panel has maximum power at around 17 volts so will need a minimum of 2 in series in a 24 volt system. There is no technical disadvantage but larger domestic sized 24 volt panels are cost effective.
[PDF Version]
We'll walk you through every step—from replacing the battery and relocating it, to installing solar, inverter/charger, alternator charging, and more—so you can follow along with your own upgrade.
[PDF Version]
A 24 volt solar system uses multiple solar panels wired in series to produce a higher DC voltage output around 24V. This 24V DC electricity is stored in batteries and converted by inverters to power 24V appliances and equipment.
[PDF Version]
Determine the Solar Panel Output: A 100-watt solar panel typically produces about 80 watts in optimal conditions. Calculate Watt-Hours Needed: Multiply the amp-hour rating by the battery voltage (100Ah x 12V = 1,200 watt-hours).
[PDF Version]